Chemical feeding device

ABSTRACT

The convenience of a medication supplying apparatus is improved. The medication supplying apparatus is equipped with a tablet case ( 1 ) having a dispensing drum for dispensing medications from an accommodating container that accommodates medications, a motor for driving the dispensing drum, a controlling means for controlling the operation of the motor, and a dispensing detection means for detecting the dispensing of a medication from the tablet case ( 1 ), wherein the controlling means reverses the motor if the dispensing detection means does not detect normal dispensing of a medication when the motor is rotated to dispense a medication.

TECHNICAL FIELD

The present invention relates to a medication supplying apparatus.

BACKGROUND ART

Conventionally, at hospitals or pharmacies, medications prescribed bydoctors are supplied to patients by using a medication supplyingapparatus (referred to as a “tablet packaging apparatus” in thepublication) disclosed in, for example, Japanese Examined Utility ModelPublication No. 575286 (B65B1/30).

The medications (tablets, capsules, etc.) in the quantities specified onprescriptions are dispensed one at a time from a dispensing drum(referred to as an “aligning board” in the publication) in the tabletcase and collected by a hopper, then packaged.

A common object of the application concerned is to provide a preferredmedication supplying apparatus with an improved medication supplyingsection in an automatic medication packaging machine, an automaticmedication filling machine, an automatic dispensing machine, or thelike.

A first object of the application concerned is to detect a fault whilemedication is being dispensed from a tablet case. A propositionregarding the detection of abnormal states has already been submitted bythe present inventor under Japanese Patent Application No. 10-275656. Inthe application, however, a medication jam, which is an abnormalcondition, is detected on the basis of the current passing through amotor. An object of the present application is to detect an abnormalcondition by a simple construction.

A second object of the application concerned is to speed up thedispensing of medications from a tablet case. The dispensing ofmedications can be sped up by speeding up a dispensing drum. On theother hand, however, there is a danger in that making an attempt tosimply achieve the speeding up will cause more medications than a targetquantity to be dispensed due to a mechanical overrun. It could bepossible to slow down the rotational speed. However, the sizes andshapes of medications are not the same, so that merely dropping down amotor output may cause a dispensing failure for some types ofmedications because of an insufficient motor output. The presentinvention is to provide a medication supplying apparatus that securelydispenses medications while restraining such an overrun.

A third object of the application concerned is to accurately count thenumber of dispensed medications. The dispensed medications are opticallydetected. Specifically, a detection optical path is formed by a lightsource (a light emitting means) and a sensor (a light receiving means).Dispensed medications interfere with the detection optical path, and thelevel of a light receiving signal from the sensor when a medicationinterfere with the detection optical path drops. Thus, the lightreceiving signal is compared with a threshold value thereby to detectthe dispensed medication.

Different types of medications have different shapes, and theinterfering cross-sectional areas thereof vary, depending on theorientations when they are dispensed, leading to significant variationsin the drop in the light receiving level when they are dispensed. Inaddition, the sensor output falls because of contamination by powderfrom medications. Hence, it is difficult to set the threshold value, andmalfunction results unless the threshold value is set at an optimumvalue. The present invention is to provide a medication supplyingapparatus that restrains malfunction.

DISCLOSURE OF INVENTION

According to the application concerned, there is provided a medicationsupplying apparatus equipped with a tablet case (1) having a dispensingdrum for dispensing medications from an accommodating container thataccommodates medications, a motor for driving the dispensing drum, acontrolling means for controlling the operation of the motor, and adispensing detection means for detecting the dispensing of a medicationfrom the tablet case (1), wherein the controlling means reverses themotor if the dispensing detection means does not detect normaldispensing of a medication when the motor is rotated to dispense amedication.

Furthermore, according to the application concerned, the controllingmeans issues an anomaly alarm if the dispensing detection means does notdetect normal dispensing of a medication even after a plurality ofcycles of reversing the motor and then rotating it in the normaldirection is repeated.

Furthermore, according to the application concerned, the controllingmeans stops the supply of power to the motor if the dispensing detectionmeans does not detect normal dispensing of a medication even after aplurality of cycles of reversing the motor and then rotating it in thenormal direction is repeated.

Furthermore, according to the application concerned, the controllingmeans determines that a medication has not been normally dispensed ifthe dispensing detection means does not detect the dispensing of thenext medication for a predetermined time after having detected thedispensing of a medication.

In addition, according to the application concerned, there is provided amedication supplying apparatus equipped with a tablet case (1) having adispensing drum for dispensing medications from an accommodatingcontainer that accommodates medications, a motor for driving thedispensing drum, a controlling means for controlling the operation ofthe motor, and a dispensing detection means for detecting the dispensingof a medication from the tablet case (1), wherein the controlling meanscounts the quantity of dispensed medications when a set target quantityof medications are dispensed, and when the count number reaches a valuethat is smaller than a target quantity by a predetermined value, itreduces the output of the motor to decrease the rotational speedthereof, then gradually increase the output of the motor from the momentthe rotational speed is decreased.

Furthermore, according to the application concerned, the controllingmeans reduces the electric power supplied to the motor thereby todecrease the rotational speed of the motor.

Furthermore, according to the application concerned, the controllingmeans integrates the difference between a target quantity and a countnumber from the moment the electric power supplied to the motor isdecreased, and the time integral amount of the difference is added tothe motor output.

Furthermore, according to the application concerned, the controllingmeans stops the supply of power to the motor when a count number reachesa target quantity.

Furthermore, according to the application concerned, there is provided amedication supplying apparatus equipped with a tablet case (1) having adispensing drum for dispensing medications from an accommodatingcontainer that accommodates medications, a motor for driving thedispensing drum, a light emitting means and a light receiving means thatmake up a detection optical path in a dispensing passage for medicationsfrom the tablet case (1), and a dispensing detection means for detectingthe dispensing of a medication by comparing the level of a lightreceiving signal from the light receiving means with a threshold value,wherein the dispensing detection means corrects the threshold valueaccording to the level of the light receiving signal obtained during anon-medication-dispensing period.

In addition, according to the application concerned, the non-dispensingperiod means the period before the operation for dispensing medicationsis started.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a tablet case of a first embodiment inaccordance with the present invention; FIG. 2 is a diagram showing adispensing detection optical path of the first embodiment; FIG. 3 is adiagram showing the dispensing detection optical path of the firstembodiment; FIG. 4 is a flowchart for explaining an operation of thefirst embodiment; FIG. 5 is a diagram for explaining the fluctuation ofa light receiving level in an early phase of the first embodiment; FIG.6 is a diagram for explaining the fluctuation of the light receivinglevel observed when sensitivity deteriorates due to contamination or thelike in the first embodiment; FIG. 7 is a diagram for explaining asituation where rotational speed is dropped before last dispensing, thena motor output is gradually increased in the first embodiment; FIG. 8 isa front view of a medication filling apparatus according to the firstembodiment; FIG. 9 is a side view of the medication filling apparatusaccording to the first embodiment; and FIG. 10 is a rear view of themedication filling apparatus according to the first embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

In conjunction with FIG. 1 through FIG. 10, a first embodiment accordingto the present invention will now be described in detail. FIG. 1 is adiagram showing a tablet case, in which a dispensing drum andmedications are shown in a perspective manner. FIG. 2 is a diagram forexplaining a dispensing detection optical path. FIG. 3 is also a diagramfor explaining the dispensing detection optical path. FIG. 4 is aflowchart for explaining an operation. FIG. 5 is a diagram forexplaining the fluctuation in a receiving light level in an early phase.FIG. 6 is a diagram for explaining the fluctuation in the lightreceiving level when sensitivity deteriorates due to contamination orthe like. FIG. 7 is a diagram for explaining an operation in whichrotational speed is reduced before last dispensing, then a motor outputis gradually increased. FIG. 8, FIG. 9, and FIG. 10 are diagrams showinga medication filling apparatus, wherein FIG. 8 is a front view thereof,FIG. 9 is a side view thereof, and FIG. 10 is a rear view thereof.

A tablet case 1 includes a space for accommodating medications (tablets)and a well-known dispensing drum 13 for dispensing the medications.

The medications dispensed from the tablet case l pass through a passage2, wherein an optical path for detecting dispensed medications isformed, and a chute 3, and moves as indicated by an arrow 6 of FIG. 9from a chute outlet 4. By preparing a bottle or a tray under the chuteoutlet 4, the medications can be supplied into the bottle or the tray.

A substrate 5 makes up a control section for specifying a requirednumber of medications (a target quantity) or for starting the dispensingfrom the tablet case, and a display section for displaying a targetquantity and the number of dispensed medications, messages, etc.

A motor 7 drives the dispensing drum in the tablet case.

An instruction entered through a control section of the substrate 5 isprocessed by a control substrate section 8. The control substratesection 8 supplies electric power for running the motor 7 to the motor7.

The tablet case 1 is shown in FIG. 1. A dispensing drum (aligning board)13 rotates to align medications 15 and dispense them one at a time to anoutlet 14. An accommodating section 12 provides a space foraccommodating medications (tablets).

The medications 15 dispensed from the tablet case 1 pass through thepassage 2 wherein an optical path for detecting dispensed medicationsshown in FIG. 9 is formed.

The optical path for detecting dispensed medications is shown in FIG. 2and FIG. 3.

In FIG. 2 and FIG. 3, an infrared light emitting device 30 irradiatesinfrared rays toward a light receiving device 31. When a dispensedmedication passes through a passage 32, the infrared beam is partiallyintercepted, resulting in a reduction in the quantity of light reachingthe light receiving-device 31. Not all the light to be reaching thelight receiving device 31 is blocked.

Hence, the output levels of the light receiving signals from the lightreceiving device 31 change in an analogue manner. The light receivingsignals are output to the 10 control substrate section 8 of FIG. 9. Thecontrol substrate section 8 monitors the changes in the light receivingsignal level so as to detect the passage (dispensing) of a medicationand count the number of dispensed medications.

The operation of the control substrate section 8 will be explained withreference to FIG. 4 through FIG. 7.

First, an outline of the operation will be explained with reference tothe flowchart of FIG. 4.

The control illustrated in FIG. 4 is begun upon receipt of a quantity ofmedications to be dispensed that is specified through the controlsection of the substrate 5 of FIG. 9 (specified quantity: specifiednumber of pieces: target number) and a medication dispensing startcommand.

First, to perform comparative operation in step 41, the quantity ofdispensed medications (the number of dispensed medications.) at thepresent point is stored. At the very beginning, the quantity is ofcourse zero. The function of a timer is initiated as the motor is turnedON and run to dispense the medications.

Next, it is checked in step 42 whether the number the dispensedmedications (tablets) has reached a specified quantity. If the specifiedquantity has not yet been reached, then the elapsed time on the timerthat has been started is checked in step 43, and if a predetermined timeT has not yet passed, then the program goes along a loop to return tostep 42.

If it is determined in step 43 that the predetermined time T has passed,then a comparison is made to determine in step 44 whether the change inthe quantity of tablets during the period T is a preset predeterminednumber N or more on the basis of the difference between the quantity ofdispensed medications stored in step 41 and the present quantity ofdispensed medications. If the determination result is NO, then the motoris stopped, and it is checked in step 45 whether the number of thereverse rotations of the motor is a preset number M or less. If it is Mor less, then the program reverses the polarity of the power source ofthe motor in step 46, and returns to steps 41 and 42.

The dispensing drum 13 dispenses medications at shorter intervals whenit is rotated at higher speed, while it dispenses medications at longerintervals when it is rotated at lower speed. During a normal operation,applying constant electric power to the motor 7 causes medications to bedispensed at substantially constant intervals. The values of N. M, and Tmentioned above vary according to the amount of electric power suppliedto the motor and the type of tablets.

In the present embodiment, the dispensing of medications is monitored todetect a failure.

If the dispensing drum is jammed with tablets, locking up the rotationof the dispensing drum, it is very likely that the jamming of thetablets can be removed by reversing the motor. When the number ofremaining tablets becomes small, making it difficult for tablets toenter a cut 13 a of the dispensing drum, reversing the motor makes iteasier for the tablets to enter the cut. When tablets run out, if nodispensed tablet is detected after the reversing operation is repeatedfor an M number of times (e.g., 3 times), then an abnormal end message(alarm) is issued and the supply of electric power to the motor isstopped to terminate the operation.

Referring now to FIG. 7 that illustrates the changes in the motoroutput, the control of the rotational speed of the motor will beexplained.

In this case, the target number (target quantity) of tablets to bedispensed is set to seven, and when the actual quantity of dispensedtablets reaches six, which is one less than the target number, thecontrol substrate section drops the output of the motor to 20%, asindicated by 71. There is a difference of one piece in the target numberand the actual number of dispensed tablets, as indicated by 72.

When the time integral amount of the difference is added to the motoroutput, the output gradually increases, as indicated by 73. When thelast one piece is dispensed at 74, the motor output is reduced to 0% at75 thereby to terminate the operation.

Thus, according to the application concerned, the rotational speed isreduced before last dispensing, and the motor output is also graduallyincreased. This is because merely dropping the motor output, on theother hand, may cause a dispensing failure due to an inadequate motoroutput; therefore, the output is gradually increased so as to enablesecure dispensing even in the case of tablets requiring high load fordispensing.

The control of dispensing detection by the control substrate section 8will now be explained by referring to FIG. 5 and FIG. 6.

FIG. 5 shows the detection in a clean-state.

Reference numeral 51 indicates a sensor output (a light receiving signallevel) before the dispensing operation begins. Based on this value, athreshold value 52 and a threshold value 53 are calculated. In thisembodiment, the threshold value 52 is defined as 80% of the output 51,and the threshold value 53 is defined as 90% of the output 51. When theoutput reduces below the threshold value 52, it is determined that thepassage starts at 54, and when the output rises and exceeds thethreshold value 53, it is determined that the passage completes at 56,thereby detecting a dispensed tablet. Reference numeral 55 indicatesthat the dispensed tablet is passing.

FIG. 6 illustrates the detection when the sensor has been contaminated.Reference numeral 61 indicates the sensor output (the light receivingsignal level) before the dispensing operation begins. Based on thisvalue, a threshold value 62 and a threshold value 63 are calculated.

In this embodiment, the threshold value 62 is defined as 80% of theoutput 61, and the threshold value 63 is defined as 90% of the output61. When the output reduces below the threshold value 62, it isdetermined that the passage has started, and when the output rises andexceeds the threshold value 63, it is determined that the passage hascompleted, thereby detecting a dispensed tablet.

Thus, the threshold values are set at appropriate values according, tothe sensor output.

Although the output reduces as a whole, the threshold value 62 and thethreshold value 63 are derived on the basis of the sensor output 61before the dispensing operation is begun. This will restrainmalfunctions.

Industrial Applicability

According to the present invention, a preferred medication supplyingapparatus can be provided.

What is claimed is:
 1. A medication supplying apparatus comprising: atablet case (1) having a dispensing drum for dispensing medications froman accommodating container that accommodates medications; a motor fordriving the dispensing drum; controlling means for controlling theoperation of the motor; and dispensing detection means for detecting thedispensing of a medication from the tablet case (1), wherein thecontrolling means reverses the motor if the dispensing detection meansdoes not detect normal dispensing of a medication when the motor isrotated to dispense a medication.
 2. A medication supplying apparatusaccording to claim 1, wherein the controlling means issues an anomalyalarm if the dispensing detection means does not detect normaldispensing of a medication even after a plurality of cycles of reversingthe motor and then rotating it in the normal direction is repeated.
 3. Amedication supplying apparatus according to claim 1 or 2, wherein thecontrolling means stops the supply of power to the motor if thedispensing detection means does not detect normal dispensing of amedication even after a plurality of cycles of reversing the motor andthen rotating it in the normal direction is repeated.
 4. A medicationsupplying apparatus according to claim 1 or 2, wherein the controllingmeans determines that a medication has not been normally dispensed ifthe dispensing detection means does not detect dispensing of the nextmedication for a predetermined time after having detected the dispensingof a medication.
 5. A medication supplying apparatus comprising: atablet case (1) having a dispensing drum for dispensing medications froman accommodating container that accommodates medications; a motor fordriving the dispensing drum; controlling means for controlling theoperation of the motor; and a dispensing detection means for detectingthe dispensing of a medication from the tablet case (1), wherein thecontrolling means counts the quantity of dispensed medications when aset target quantity of medications are dispensed, and when the countnumber reaches a value that is smaller than a target quantity by apredetermined value, it reduces the output of the motor to decrease therotational speed thereof, then gradually increase the output of themotor from the moment the rotational speed was decreased.
 6. Amedication supplying apparatus according to claim 5, wherein thecontrolling means reduces the electric power supplied to the motorthereby to reduce the rotational speed of the motor.
 7. A medicationsupplying apparatus according to claim 6, wherein the controlling meansintegrates the difference between the target quantity and the countnumber from the moment the electric power supplied to the motor isreduced, and the time integral amount of the difference is added to themotor output.
 8. A medication supplying apparatus according to any oneof claims 5 to 7, wherein the controlling means stops the supply ofpower to the motor when the count number reaches the target quantity. 9.A medication supplying apparatus comprising: a tablet case (1) having adispensing drum for dispensing medications from an accommodatingcontainer that accommodates medications; a motor for driving thedispensing drum; a light emitting means and a light receiving means thatmake up a detection optical path in a dispensing passage for medicationsfrom the tablet case (1); and a dispensing detection means for detectingthe dispensing of a medication by comparing the level of a lightreceiving signal from the light receiving means with a threshold value,wherein the dispensing detection means corrects the threshold valueaccording to the level of the light receiving signal obtained during anon-medication-dispensing period.
 10. A medication supplying apparatusaccording to claim 9, wherein the non-dispensing period means the periodbefore the operation for dispensing medications is started.